Hi,
All of the defaults settings in word are stored in a template Normal.dot under the MS Office folder and templates.
If you open up a blank copy of Word and go File New and Select Blank document and also in the bottom right also select template. Then after you have resaved the template and changed you have made text, colours, fonts etc will load with Word.
If you cannot save the template (because it is already open) then save it under a different name normal1.dot close Word delete Normal.dot and then rename yours to Normal.dot
Unfortunately Excel does not get its settings though a template and I don't know how to change the default selected colour
I hope this helps